浅埋偏压地段隧道工程施工技术研究

Study on Construction Technology of Bias in Shallow Section of Tunnel

在隧道轴线与地表山坡走向或岩层走向夹角较小时,工程开挖后将会产生较为明显的偏压现象,隧道开挖后可能会产生较大的不均匀变形。为分析解决隧道浅埋段偏压的问题,文章分析了浅埋偏压现象的产生机理,进行各种施工方法的数值模拟,研究了隧道轴线与山坡及岩层相交形式对隧道围压的影响。由模拟计算结果确定了隧道洞口采用超短台阶预留核心土的施工方法,提出相关的施工工艺,并可为土层性质相近的隧道工程浅埋段施工提供技术参考。

When the angle between the tunnel axis and the direction of the surface slope or the direction of the strata is small,there will be obvious bias phenomenon after the excavation of the project,and the uneven deformation may occur after the excavation of the tunnel.In order to analyze and solve the problem of bias in shallow section of tunnel,the paper analyses the mechanism of the phenomenon of bias in shallow section,carries out numerical simulation of various construction methods,and studies the influence of the intersection form of tunnel axis,hillside and rock stratum on the surrounding pressure of tunnel.Based on the simulation results,the construction method of reserving core soil with ultra-short steps at tunnel entrance is determined,and relevant measures are put forward.